Step 3.5 Flash
Access Step 3.5 Flash through one API key. StepFun's fast model.
StepFun's fast inference model. Budget-friendly Chinese provider with 262K context window.
No credit card required. Takes 30 seconds.
2,400+
Developers
1.2M+
API calls served
100+
Endpoints
$0.01
Per call
Yep, that's it.
Try it live
Send a message and see Step 3.5 Flash respond in real time.
Maximum tokens in the response.
Real-time tokens
Context Window
262K tokens
Max Output
66K tokens
Input Price
$0.14 / 1M tokens
Output Price
$0.42 / 1M tokens
Strengths
StepFun's fast-inference tier is tuned for low-latency responses on high-throughput workloads.
At $0.14 per 1M input tokens, it offers budget pricing for high-volume text tasks.
Handles multiple languages, useful for international applications and translation tasks.
Built by a Chinese provider with strong Chinese-language understanding and generation.
Quick start
Copy this snippet and start making calls with Step 3.5 Flash.
const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
method: 'POST',
headers: {
'x-api-key': 'YOUR_API_KEY',
'Content-Type': 'application/json',
},
body: JSON.stringify({
"model": "stepfun/step-3.5-flash",
"messages": [
{
"role": "user",
"content": "Explain API gateways in 2 sentences."
}
],
"maxTokens": 256
}),
});
const { data } = await res.json();
console.log(data.message.content);Why use Step 3.5 Flash through YepAPI?
Step 3.5 Flash API: StepFun's fast, budget model
Step 3.5 Flash is StepFun's fast-inference model, a budget-friendly option with strong Chinese-language ability and a 262K context window. YepAPI serves it through one OpenAI-compatible endpoint.
Your single YepAPI key also reaches DeepSeek, Claude, Grok, Gemini, and more, plus SEO, SERP, and scraping endpoints, so Step 3.5 Flash can sit alongside your search and data tools.
What is Step 3.5 Flash?
Step 3.5 Flash is a fast-inference model from StepFun, a Chinese AI provider. It is built for speed and low cost on high-throughput workloads, with a 262,144-token context window and up to 65,536 output tokens. Its defining strengths are budget pricing and strong Chinese-language understanding, alongside broader multilingual capability, which makes it a good fit for applications serving Chinese-speaking users or working with Chinese-language content. As a Flash-tier model it prioritizes responsiveness and affordability over the deepest reasoning, suiting classification, translation, and routine generation at volume.
Build with Step 3.5 Flash via YepAPI
Use YepAPI's OpenAI-compatible /v1/ai/chat endpoint with any OpenAI client. Set the base URL, add your key, and set the model string to Step 3.5 Flash; your existing messages and parameters carry over. Switching models is a single string change. Because one key reaches the full catalog, you can route Chinese-language and high-volume tasks to Step 3.5 Flash and other work to different models, all from a single integration.
Step 3.5 Flash API pricing — $0.14 input / $0.42 output per 1M tokens
Step 3.5 Flash costs $0.14 per 1M input tokens and $0.42 per 1M output tokens, putting it firmly in budget territory. At these rates, high-volume translation, classification, and generation jobs stay inexpensive, and the 262K context window means you can include long inputs without changing the cost model. Per-token billing keeps large batch runs predictable.
Step 3.5 Flash for Chinese-language and multilingual tasks
Step 3.5 Flash is a strong choice when your workload centers on Chinese content or mixed multilingual text, translation, localization, classification, and generation for Chinese-speaking audiences. Its 262K context handles long documents, its Flash tuning keeps responses fast, and the low price makes it practical to run these tasks at scale, especially for products targeting Chinese markets that need a cost-efficient, locally strong model.
Try Step 3.5 Flash free
New YepAPI accounts come with $5 in free credit and no card required. That covers plenty of Step 3.5 Flash usage, enough to test its Chinese-language and multilingual quality on your own data, compare it with other models on the same key, and confirm fit before adding any payment method.
Start generating in 30 seconds
$5 free credit on signup. No credit card required. Pay per call.
What developers say
“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Frequently asked questions
StepFun's fast inference model. Budget-friendly Chinese provider with 262K context window.
Input tokens cost $0.14 per 1M tokens and output tokens cost $0.42 per 1M tokens through YepAPI. No monthly minimums — you only pay for what you use.
Sign up for a free API key, then send requests to the /v1/ai/chat endpoint.
Step 3.5 Flash supports a 262K token context window with up to 66K output tokens per request.
Ready to use Step 3.5 Flash?
$5 free credit on signup. No credit card required. Pay per call.
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